Electromagnetic device



- 1,616,180 F. E. FIELD EIJECTROMAGNETICIDEVIGE Feb. 1 1927.

Filed Dec. 28'. 1921 Wren/0r.

Patented Feb. 1, 1927.

.UNITED STATES PATENT orrlca.

rm: 3. FIEI: O11! SOMEBV comm, INCORPORATED,

This invention relates to electromagnetic devices, and particularly to means for controlling the resonance frequency ofsuch devices.

. of electromagnets.

It is well known that an electromagnet or.

a certain inductance will resonate with its internal capacit at a definite frequency. However, it is coil havin freqpency without (an "ties of the coil.

eature of the'invention the resonance freuency of such a coil is changed to some pres etermined higher point by inserting in the core of the coil a sheet or lamination of soine stood electrical conductor, such as copper.

the leakage, of the coil may be controlled.

' ntnc'rnouaennr c mivrcn.

Application filed December as, 1921. Serial No. 525,504.

requently de- ILLE, NEW JERSEYyASSIGNOR TO WESTERN ELECTRIC OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

pacity is fixed. The resonance fre uency of the coil may be raised to a still hig er value by increasing the number of sheets of copa per in the core. It will be seen that by vary- 6 It is an object of the invention to provide ing the thickness of the. copper or by into means for adjusting the resonance frequency creasin the number of suchlaminations it is possi le to control the resonance frequency of the coil. By properly computing the value of the non-magnetic conductor inserted in this manner' it is possible to control the E5 amount of leakage of a coil. In Fig. 2 the sired to raise this resonance point to a higher same arrangement is employed except that destroying the. good the .coil 6 is provided with an external rec- In accordance with a tangular laminated 'core 7. These laminations are held in place by a screw 8 at each corner of the core or by any clamping means well understood in the art. This core is readily assembled and it is simply necessary to loosen the clamping screws 8 in order toy By a proper insertion of such laminations replace some of the magnetic laminations 05 with laminations of non-magnetic conduct- Other objects and advantages of the ining material, such as is shown at 9. It is forth in detail in the to beunderstood that the invention is not vention will be set following description,

pointed outjin the appended claim.

What 1s claimed is:

and particularly limited-to the specific construction herein shown, and described except as defined by the scope of the following claim,

An electromagnetic device comprising a rectangular core, certain parts being broken winding having effective capacity in shunt 30 away to more clearly illustrate the invention. thereto and a core for said windin said ,corebeing made up of laminations o magnetic material and laminatio'ns of electrically conducting non-magnetic material, the num- Referring to llie-drawing,'Fig. 1 shows a rial, is wound in the, usual mannerf with her and thickness of the magnetic and nonsuperimposed layers of a conductor 4. A

magnetic laminations being relatively proplurality, of laminations of copper 5 are'inportioned with reference to-a resonance freserted in the corefor the purpose of raising its reso ance frequency.

I quency' which the'device i At low frequencles whereby the efiective inductance of the des desired to possess ed y fl 1085 in these Sheets i vice is. controlled to resonate with the said 4" not be a preciable, but as the frequency goes up the 0s increases as the square of the frequency.

frequency.

eifective shunt capacity at the said resonance $5 In witness whereof, I hereunto subscribe my name this 20th day of December A. D.,

-rerun; E. FIELD.- 

